When produce, such as cauliflower, cabbage, bell peppers and the like is harvested, workers in the field will pack the produce in cartons. These cartons or boxes are generally rectangular in shape and normally have side openings for facilitating holding of the cartons. Generally they are stacked on pallets and the stacked cartons in turn then transferred to a flat bed truck or other transportation means to be shipped to a distribution point.
At the distribution point, the cartons are immediately placed in a large refrigerated building for the purpose of removing field heat from the produce as quickly as possible. The produce essentially is cooled to a temperature of from 40.degree.-45.degree. F. Thereafter, the produce can be shipped to various distribution points as by refrigerated trucks, railroad cars, or the like.
It is found in practice, that the shelf life of most produce is a function of how quickly the field heat can be removed from the produce once it has been harvested. If considerable time lapses from the time of harvesting to the time of initial cooling down of the produce, the overall shelf life at a retail store is substantially reduced. Any system, accordingly, which will speed up the process of pre-cooling or removing field heat from the produce after harvesting will substantially increase the shelf life and be beneficial to all concerned.